According to reports, one dog has died and several have been taken seriously ill after contracting babesiosis, caused by a parasite carried in the ticks.
There are now fears the disease could spread from the area of Essex where the dogs were walked, despite measures to contain it.
Speaking to the BBC, Clive Swainsbury, a vet at the Forest Veterinary Centre in Harlow, said he had seen some of the four infected dogs.
Fire destroys huge area of land at Great Denham Golf Course
Anglian Water rules out hosepipe ban for Bedford households
'Sophisticated crime group' behind £1.1m stolen from Luton council that was destined for a Bedford school
Man charged with burglary and assaulting an emergency worker in Flitwick
Bedford bus company revises timetable after passenger numbers review
The parasite leads a host dog’s immune system to attack its own blood cells, causing severe anaemia that requires blood transfusion to treat.
Mr Swainsbury warned that the disease will be hard to detect as vets in the UK are not used to it.
At the same time, efforts to contain the spread could be thwarted by wild animals.
He said: “At present we have a very well-defined area.
“The problem in the future is that every female tick will lay a couple of thousand eggs and all those offspring from that disease will also carry the disease.
“As mammals move around they will start spreading the disease. Although you can advise dog walkers not to go there, it’s possible that foxes and other animals will transport these ticks.”
According to website PetMD.com, owners are advised to do a thorough body check of their dog to find ticks, which are visible to the naked eye but can be drawn to dark, hidden areas of the animal’s body such as ears, groin and between the toes.
Signs of ticks include dogs excessively scratching or licking a particular area.
To remove a tick, owners are advised to use tweezers to grip the tick by the head and pull it straight out, and not to twist, burn or apply anything to the skin. To kill the tick once it has been removed, put it in a small amount of alcohol, rather than squash it.